Bulldozer



Patented a. 21, 1941 BULLDOZER Carl A. Gustafaon, Peoria, lli., assignorto Caterpillar Tractor 00., S

poration of California Application November 13, 1939, Serial No. 304,019

My invention relates to bulldozers, and more particularly to a bulldourattachment especially adapted for use on a self-propelled motor grader.

A type of such grader is illustrated in my prior Patent No. 2,034,141.In graders of this character, it is frequently desirable to have at thefront of the machine's scraper blade which may be employed for so-calledbulldozing work, namely to push material in front of the machine. Suchwork can not be conveniently done by the grader blade which isunderneath the machine intermediate the ends thereof, because the frontwheels of the machine would have to travel over the material to bebulldozed.

My invention has as its objects, among others, the provision of animproved attachment which may be conveniently mounted on the front endof a self-propelled or motor grader; which is of simple and economicalconstruction; in which the bulldozer blade may be adjusted to variouspositions suitable for the work to be done; in which such blade may belifted completely out of the way when not desired for use so as not tointerfere with the normal work that the grader may be called upon toperform; and which is simple and easy to operate and control from theoperator's station on the machine. Other objects of the invention willbecome apparent from a perusal of the following description thereof.

Referring to the drawings:

Fig. 1 is a partially schematic side elevational view of a form ofself-propelled grader manufactured by my assignee, with the bulldozerattachment of my invention connected to the grader.

Fig. 2 is a plan view of the front end of the machine and the bulldozerattachment; portions of the structure being omitted and broken away todisclose more clearly the construction.

Fig. 3 is a side elevational view of the structure shown in Fig. 2;portions of the construction being shown in section and broken away todisclose more clearly the construction.

Fig. 4 is an end view looking in the direction of arrow 4 in Fig. 2.

'Fig. 5 is a schematic view illustrating the bulldozer adjusted at anoblique angle with respect to the line of draft of the machine.

Fig. 6 is a section of the bulldozer shoe taken in a plane indicated byline 8-8 in Fig, 3.

Although the bulldozer attachment of my in- Leandra, cum, a corthemachine and providing power for adjusting various earth workingimplements on the machine, is mounted at the rear; and an operator'sstation I is positioned in front of engine 4. Power from engine 4 istransmitted to power control box 1, in the manner disclosed in mypreviously mentioned patent, through which by manipulation of variouscontrol handles 8, adjustments can be made to lift arms 9 for adjustinggrader blade II and to lateral shift mechanism If for the grader blade.Steering of the machine is effected manually by means of steering wheell3 connected to steering shaft il in turn connected to suitable steeringmechanism in housing It.

The bulldozer attachment comprises a frame M which supports the entirebulldozer mechanism, and which is adapted for detachable mounting as aunit on the front end of the grader. Such frame comprises side members22 detachably secured at their rear ends to the grader main frame I bymeans of bolts 23, and which are braced near their front ends by tubularbrace 24; the brace '24 being rigidly connected to side members 22through depending plates 26 which vention may be employed with any ofthe various are braced adjacent their lower ends by tubular brace 21.Adjacent their rear edges and intermediate'their ends, plates 26 areprovided with bosses 28 secured to cross shaft 29, supported in frontbolster 3| of the grader and which normally provides a mounting for ascarifier attachmerit adapted to be mounted on the grader.

When my bulldozer attachment is employed. the scarifler attachment, ifon the machine, is removed therefrom. From the preceding, it is seenthat the bulldozer attachment of my invention is rigidly supported onthe front end of the grader.

Means is provided for supporting a straight bulldozer blade 32 fromframe 2i including a substantially parallel lift linkage for enablingvertical raising or lowering of the blade with respect to the ground.Such vertical movement is desirable because it enables the blade to beaccurately positioned on the ground, and precludes dragging of the bladeupon lifting or lowering thereof when set at an oblique angle to theline of draft of the machine. The blade is adjustably connected to asupporting structure therefor in the form of cross piece 33, in a mannerto be described more fully hereinafter. Adjacent each end of cross piece33 is a pair of ears 34 in which are pivotally connected spaced-strutsor arms 36 in turn pivotally connected to the lower ends of plates 26.An upright post member 31 is fixedly attached to cross piece 33 at themiddle thereof, and has pivotally connected to its upper end arm orstrut 38 which is substantially parallel to struts 38, and is adjustableas to length by means of turn buckle 39 having handle ii to enableturning of the turn buckle. The end of arm 38 opposite to the endpivotally connected to against lateral thrust by cross brace 44 which atits front end is pivotally connected to cross piece 33 adjacent thefront of one of struts 36, and adjacent its rear end is pivotallyconnected to a plate 28 adjacent the rear of the other of struts 36. Arm38 also cooperates to take up rearward thrust but being adjustable as tolength, it also performs the function of enabling adjustment of thepitch of the blade about the horizontal pivotal mounting therefor at 34.

Since the ends of struts 36 and 3B are all pivotally connected, it isapparent that they allow the bulldozer blade to be lifted out of contactwith the ground, or lowered into contactwith the ground; and because ofthe substantially parallel relationship of these members, a parallellift linkage obtains to provide the advantages previously pointed out.Lift means mounted entirely on frame 2| so as to form a part of theentire attachment, is provided for lifting or lowering the bulldozerblade. Such lift means comprises shaft 46 joumalled at the front of sidemembers 22, and extending beyond the outer sides of such side members;the shaft projecting through sleeve 41 fixedly attached to the left sidemember 22. Also shaft 46 projects through gear housing 48 fixedlyattached to sleeve 41 and to the right side member 22. Thus, sleeve 41and gear housing 48 provide additional reenforcing means for sidemembers 22.

A worm wheel 49 within gear housing 48 is fixedly attached to shaft 46and meshes with worm 5| journalled in the top of gear housing 48. Theshaft for worm if has secured thereto adjacent its front end, gear52enclosed within gear compartment 53 of gear housing 48, and whichmeshes with pinion 54 also enclosed within gear compartment 53. Pinioni4 is secured to shaft 54 journalled in and projecting outside of gearcompartment 53. From the preceding, it is seen that rotation of shaft 56in either one of opposite directions will effect corresponding rotationof shaft 43 in either one of opposite directions. For effecting rotationof shaft 56, I utilize the power control mechanism 1 already on thegrader. For this purpose, shaft 53 is universally connected by universalcoupling 51 to extensible shafting 58, which in turn is universallyconnected toshafting 53, the rotation of which is reversiblycontrollable from power control box I in the manner disclosed in myPatent No. 2,034,141.

Lift linkage is connected between shaft 46 and cross piece 33 comprisingcrankarms 3i fixedly attached to the ends of shaft 46, and pivotallyconnected to arms 62; such arms 62 being resiliently connected to crosspiece 33 to allow the bulldozer blade. to ride over obstructions andthereby preclude injury to the lifting mechanism. To provide suchresilient connection, the lower ends of arms 62 are slidably connectedin swivel bolts 63 pivoted in ears 34, and have nuts 34 underneathswivel bolts 63 to provide support for the bulldozer blade duringlifting or lowering thereof; springs 66 about arms 62 being interposedbetween swivel bolts 63 and collars 31 fixedly attached to arms 62, tothrust the blade resiliently in contact with the ground.

The crankarms 6| are rotatable through 360. Therefore, there is nodanger of damaging the in position.

lifting mechanism. by lifting the blade too high because the crank armscan travel through the position which they have when the blade is liftedto its maximum height above the ground; and no special automatic controlmeans is required to stop lifting of the blade. In this connection,lifting or lowering of the blade may be accomplished, if desired, byrotating worm 5! always in one direction. When lifted to any position,the worm BI and worm wheel 48 drive provides a self-locking means tohold the blade The entire attachment may be readily and convenientlydetachably mounted on the grader; and when so mounted, it is apparentthat it will not interfere with the normal operations of the graderblade ll because when it is desired to use such grader blade for thework for which it is intended, with the attachment on the machine, thebulldozer blade 32 may be lifted completely out of the way.

Means is provided for adlustably mounting the bulldozer blade on itssupporting structure 33, for both endwise and angular adjustment. Suchbulldozer blade, which is arcuately shaped. has cutting edge H adjacentthe lower edge thereof, and is braced along the rear face by channel 12welded thereto: upper and lower reenforcing plates I3 being fixedlywelded to the blade and to channel 12. Adjacent each end thereof, thebulldozer blade has secured thereto a pair of spaced horizontallyextending flanges I4 which are positioned one above the other and areprovided with a group of fastening stations 16 in the form of spacedholes. Such spaced groups of fastening stations 13 provide means foradjustable attachment of the bulldozer blade to cross piece 33 by meansof bolts 11 adapted to be passed through selected of such fasteningstations 16, and through a pair of apertures formed in cross piece 33,one adjacent each end of the cross piece. Because of the plurality offastening stations 16 in each group thereof, it is apparent that bypassing of bolts 'II through selected ones of such fastening stations,the bulldozer blade may be connected in any one of a plurality ofendwise positions at a right angle to the line of draft. If desired, thespaced groups of fastening stations may be formed in cross piece 33 anda single fastening station adjacent each end of the bulldozer structure,but the described arrangement is preferred.

Under some circumstances, it may be desirable to position the bulldozerblade at an oblique angle with respect to the line of draft. Thedescribed mounting means for the bulldozer blade enables this to beaccomplished by the use of an auxiliary strut I8 which when thebulldozer blade is connected so as to extend at a right angle to theline of draft performs no function, but for convenience is connected toone of fastening stations I6, and to ear 19 at the right end of thebulldozer blade, as is illustrated in Figs. 2 and 4. When it is desiredto position the bulldozer blade at an oblique angle with respect to theline of draft of the machine to the position illustrated in Fig. 5, forexample, the righthand bolt II in Fig. 2 may be removed, the bulldozerblade pivoted about the left-hand bolt 'I'I in Fig. 2, strut vI8disconnected from the position shown in Fig. 2. and reconnected to theright end of cross piece 33 and to the selected one of the right-handgroup of fastening stations 16. In this connection, the spaced groups offastening stations 13 also permit adjustment of the bulldozer blade toany selected one of a plurality of oblique positions, by selection ofthe fastening station H5 in one group thereof to which one end of crosspiece 33 is to be connected and selection of the fastening station I8 inthe other group thereof to which the strut I8 is to be connected. Fig. 5illustrates the bulldozer blade set at an oblique angle so as to directmaterial to the left of the machine, but such blade may also be set atan opposite oblique angle to direct material to the right side of themachine, in the manner previously explained.

It is desirable to have the lower edge of the cutting edge 1| slightlyabove the grade line or ground; and for this purpose, the bulldozerblade is preferably supported at each end on shoes 82. Each shoe has anupright stud 83 which passes through a plate 84 secured to the bulldozerblade; and by adding or removing shims 86 between the shoe and plate 84.adjustment of elevation of the cutting edge with respect to the groundmay be obtained. To prevent stud 83 from becoming sheared as thebulldozer blade moves along the ground, a serrated plate 81 is fixedlyattached to each shoe 82 about stud 83, and engages correspondingserrations in plate 88 also about stud 83; the entire assembly of eachshoe being tightly held together by a nut 89.

I, therefore, claim as my invention:

1. The combination with a self-propelled motor grader of the typeincluding a main frame and a grader blade carrying frame supportedunderneath said main frame; of a bulldozer attachment mounted on thefront end of said main frame including a bulldozer blade, a supportingstructure for said blade, means connected to said supporting structureincluding a worm and worm wheel drive for raising or lowering saidblade, means connected to said supporting structure for adjusting thepitch of said blade including an adjustable turn buckle, and meansenabling angular adjustment of said blade on said supporting structure.

2. A bulldozer comprising a bulldozer blade structure, a supportingstructure therefor, means including spaced groups of fastening stationson one of said structures for supporting said blade at a right angle to,the line of draft of said bulldozer and in any selected one of aplurality of endwise positions, and means for positioning said blade atany selected one of a plurality of oblique angles with respect to saidline of draft including asingle auxiliary strut adapted to be connectedbetween said structures at either end thereof to selected of saidfastening stations and which forms no functional part of such connectionwhen said blade is at a right angle to Said line of draft.

' 3. A bulldozer unit adapted to be detachably mounted on a vehiclecomprising a frame attachable on said vehicle, arms pivotally connectedto said frame, a cross member pivotally connected to said arms, abulldozer blade mounted on said cross member, an upright member securedto said cross member, a turn buckle substantially parallel to said armsand pivotally connected to said upright member and to said frame toprovide for substantially vertical movement of said blade with respectto the ground, said turn buckle being adjustable to vary the pitch ofsaid blade, and means for lifting or lowering said blade comprising aself-locking worm and worm wheel drive mounted on said frame.

4. A bulldozer unit adapted to be detachably mounted on a vehiclecomprising a frame attachable on said vehicle, arms pivotally connectedto said frame, a bulldozer blade, means pivotally connecting said bladeto said arms, an upright member connected to said blade, a turn bucklesubstantially parallel to said arms and pivotally connected to saidupright member and to said frame to provide for substantially verticalmovement of said blade with respect to the ground, said turn bucklebeing adjustable to vary the pitch of said blade, and means for liftingor lowering said blade comprising a self-locking worm and worm wheeldrive mounted onsaid frame.

5. In a self-propelled vehicle having a frame, a bulldozer attachmentmounted on said frame including a bulldozer blade, a supportingstructure therefor, lower arms connected to said frame for pivotalmovement about a horizontal axis, said supporting structure beingconnected to said arms forpivotal movement about a horizontal axis toprovide for adjustment of the pitch of said blade, an upright membersecured to said supporting structure, an upper arm pivotally connectedto said upright member and to said frame, said upper arm beingadjustable as to ef-- fective length to adjust the pitch of said bladein cooperation with said pivotal connection of said blade supportingstructure on said lower arms, and said upper arm being substantiallyparallel to said lower arms to provide for substantially verticalmovement of said blade with respect to the ground, means for lifting orlowering said blade together with all of said arms, and means enablingangular adjustment of said blade on said supporting structure.

6. A bulldozer unit adapted to be deta chably mounted on a vehiclecomprising a frame attachable on said vehicle, a bulldozer blade, lowerstrut means connected to said frame for pivotal movement about-ahorizontal axis, said blade being pivotally connected to said strutmeans for pivotal movement about a horizontal axis to provide foradjustment of the pitch of said blade, an upright member connected tosaid blade, upper strut means pivotally connected between said uprightmember and said frame, the length of said upper strut means incooperation with said pivotal connection of said blade on said lowerstrut means determining the pitch of said blade, and means mounted onsaid frame including driving mechanism and a linkage connection betweensaid driving mechanism and said blade for tachable on said vehicle, abulldozer blade, lower.

strut means connected to said frame for pivotal movement about ahorizontal axis, said blade being pivotally connected to said strutmeans for pivotal movement about a horizontal axis to provide foradjustment of thepitch'of said blade, an upright member connected tosaid blade, upper strut means pivotally connected between said uprightmember and said frame, said upper strut means being adjustable as to'eflective length to adjust the pitch of said blade in cooperation withsaid pivotal connection of said blade on said lower strut means, andsaid upper strut means being substantially parallel to said lower strutmeans toprovide for substantially vertical movement of said blade withrespect to the ground,

and means for lifting or lowering said blade comprising a self-lockingworm and worm wheel drive mounted on said frame.

CARL A. GUSTAFSON.

